Project Abstract Syncope is a complex presenting symptom that requires thoughtful and efficient evaluation to determine the etiology of a patient's loss of consciousness. Prevalence rates of syncope have been reported as high as 41%, with recurrent syncope occurring in 13.5%. A common symptom, approximately 1% to 3% of all emergency department (ED) visits (as many ED visits as atrial fibrillation) and up to 6% of all hospital admissions are due to syncope. The prognosis among patients with syncope depends on the etiology and underlying cardiovascular condition. A cardiac etiology of syncope is associated with significantly higher rates of morbidity and mortality than other causes such as vasovagal reflex mediated or orthostatic hypotension. The Framingham study documented a doubling of the risk of death among participants with cardiac syncope compared with those with non-cardiac syncope. Notably, experiencing syncope affects patients' quality of life (QoL), and those with more frequent syncope report poorer QoL with perceptions of low overall physical and mental health and impairment in activities of daily living. The QoL among patients with recurrent syncope appears equivalent to severe rheumatoid arthritis and chronic low-back pain in an adult population. Though research in the past 25 years provides substantial understanding of the pathophysiology of particular etiologies of syncope, the diagnostic approach to such a perplexing symptom remains difficult and efficient diagnosis remains elusive. The major challenge in the evaluation of patients with syncope is that most patients are asymptomatic at the time of their presentation. Because of concerns that patients presenting with syncope are at risk for an impending catastrophic event, overuse and inappropriate use of testing and hospital admission are common. Aiming to provide guidance on optimizing the evaluation and management of syncope, a collaboration of the American College of Emergency Physicians, Society for Academic Emergency Medicine, American College of Cardiology (ACC), American Heart Association (AHA) and Heart Rhythm Society (HRS) issued a Guideline for the Evaluation and Management of Patients with Syncope in 2017. Adopting a standardized approach to syncope based on this guideline offers an effective opportunity for delivering high value care to patients suffering this distressing and potentially dangerous event. Aiming for more rapid translation from guideline to clinical practice and improved health, the proposed study will identify barriers and facilitators for implementation of an evidence-based, high value approach to diagnosis and management of patients presenting with syncope. The research team will develop a multi-level, multi-component implementation strategy for evidence-based syncope evaluation and management and plan for a subsequent hybrid effectiveness-implementation trial, guided by the Consolidated Framework for Implementation Research (CFIR).